This invention relates generally to the electronic production of musical tones and, more specifically, to a system for producing musical patterns of bass tones having a tonic note selected by an instrumentalist.
In the area of automatically controlled musical instruments devices are known which automatically yield musical patterns that may be selected at will by an operator or instrumentalist. One category of such device is the rhythm accompaniment device, which is adapted to produce various rhythms (e.g., fox trot, samba, waltz, etc.) by utilization of various percussion instrument sounds (e.g., drums, follow etc.), the particular rhythm to be played being selectable by the operator or instrumentalist. By utilization of a rhythm accompaniment device in connection with the play of a basic instrument, such as an electronic organ, an instrumentalist can play the melody and the device will provide a rhythm accompaniment, so that the end effect is that of a full band. Rhythm accompaniment devices play on their own, essentially independent of what the instrumentalist is doing. Normally the instrumentalist will condition his beat to coincide with that of the rhythm accompaniment device, but some such devices can be modified to following the beat of the instrumentalist; however, even in the latter case, the only change in the musical output of the device is the beat or speed of the music -- there is no change in the basic sound of the music.
A primary problem in providing accompaniment notes or tones is that when a musical note or tone is produced there is a much greater interaction with the music being played by the instrumentalist than when a rhythm accompaniment is being produced. In the latter case, it is only necessary to match the beat of the instrumentalist and the rhythm accompaniment, whereas in the former it is necessary that the played notes or tones produce the proper musical effect when combined with the notes being played by the instrumentalist. As a result, it is necessary that the instrumentalist have control over the tonal nature of the accompaniment being produced.
One known system for providing tonal accompaniment arrangements is that described in Wangard U.S. Pat. No. 3,688,009, and automatically produces a pattern of notes in response to choice of the basic or tonic note by the instrumentalist. The system includes a generator capable of generating a plurality of different predetermined tone sequence patterns, the desired pattern (appropriate to the selection to be played by the instrumentalist and/or the accompanying major rhythm accompaniment) being selected by a push button on the organ console. For each of the patterns, the rhythm generator produces a pattern of driving signals, each of which represents a note in a group of musical notes, which are applied to a tone generator along with reference signals having distinctive voltage magnitudes representative of respective tonic notes having a predetermined interval relationship, and control the generator of the tone pattern in accordance with the driving signals. Selection of the reference signals to be applied to the tone generator is accomplished by operation of the pedal keys of the organ; when a pedal key is played, instead of the single note normally associated with that pedal being played, the selected pattern is generated, the first, or basic note of which corresponds to the pedal depressed, followed by a related group of notes having predetermined interval relationships. As long as that particular pedal is depressed, the pattern automatically repeates itself at a rate determined by a suitable clock, which usually is the same synchronizing clock utilized in the major rhythm unit of the organ, so as to achieve timing between the major rhythm unit and the bass accompaniment device. If, now, a different pedal key is played, a pattern of notes having the same interval relationship is generated, with corresponding notes of the group spaced by the difference in frequency between the tonic notes associated with the two pedals; thus, the instrumentalist can, by playing different ones of the pedal keys, shift the nominal frequency of the preselected pattern "up and down the scale" to provide an added dimension to the playing of music; the effect is known in the trade as "walking bass" and has long been used with commercial success.
While the functional performance of the above-described "walking bass" feature has been satisfactory and well received, it is relatively expensive to manufacture and occupies more space within the organ console than would be desired. A primary reason for this is that the feature was designed as an add-on to a previously available pedal tone generating system with the consequence that some of the circuitry of the pedal tone generator had to be duplicated in the system for producing bass tone patterns; that is, the pedal tone generator and bass tone generating system were not efficiently integrated, resulting in unnecessarily high manufacturing costs to achieve the desired function and also in the requirement that the instrumentalist had to actuate a number of control buttons on the organ console in order to establish a desired pattern.
It is a primary object of the present invention to provide a pedal generator for an electronic organ that will automatically produce a desired pattern of musical tones based upon a tonic note selected by an instrumentalist that is of simpler design, and less costly to manufacture, than systems heretofore available.
Yet another object of this invention is to provide a compact and relatively inexpensive pedal tone generator also having the capability of producing patterns of bass tones having a tonic note selected by an instrumentalist.